1 The behaviour of predators can be an important factor in the transmission success of an insect pathogen. We studied how Calosoma sycophanta influences the interaction between its prey [Lymantria dispar (L.) (Lepidoptera, Lymantriidae)] and two microsporidian pathogens [Nosema lymantriae (Microsporidia, Nosematidae) and Vairimorpha disparis (Microsporidia, Burellenidae)] infecting the prey. 2 Using laboratory experiments, C. sycophanta was allowed to forage on infected and uninfected L. dispar larvae and to disseminate microsporidian spores when preying or afterwards with faeces. 3 The beetle disseminated spores of N. lymantriae and V. disparis when preying upon infected larvae, as well as after feeding on such prey. Between 45% and 69% of test larvae became infected when C. sycophanta was allowed to disseminate spores of either microsporidium. 4 Laboratory choice experiments showed that C. sycophanta did not discriminate between Nosema‐infected and uninfected gypsy moth larvae. Calosoma sycophanta preferred Vairimorpha‐infected over uninfected gypsy moth larvae and significantly influenced transmission. 5 When C. sycophanta was allowed to forage during the latent period on infected and uninfected larvae reared together on caged, potted oak saplings, the percentage of V. disparis infection among test larvae increased by more than 70%. The transmission of N. lymantriae was not affected significantly in these experiments. 6 Beetles never became infected with either microsporidian species after feeding on infected prey. 7 We conclude that the transmission of N. lymantriae is not affected. Because no V. disparis spores are released from living larvae, feeding on infected larvae might enhance transmission by reducing the time to death and therefore the latent period.

中文翻译：

---

林毛虫猎手Calosoma sycophantaon对吉普赛蛾Lymantria dispar幼虫中微孢子虫传播的影响

1 捕食者的行为可能是昆虫病原体传播成功的重要因素。我们研究了 Calosoma sycophanta 如何影响其猎物 [Lymantria dispar (L.) (Lepidoptera, Lymantriidae)] 和两种微孢子虫病原体 [Nosema lymantriae (Microsporidia, Nosematidae) 和 Vairimorpha disparis (Microsporidia, Burellenidae they)] 之间的相互作用。2 通过实验室实验，C. sycophanta 被允许在受感染和未受感染的 L. dispar 幼虫上觅食，并在捕食时或之后用粪便传播微孢子虫孢子。3 甲虫在捕食受感染的幼虫时以及在以此类猎物为食后传播 N. lymantriae 和 V. disparis 的孢子。当 C. sycophanta 被允许传播任一微孢子虫的孢子时，45% 到 69% 的测试幼虫被感染。4 实验室选择实验表明，C. sycophanta 不区分 Nosema 感染和未感染的吉普赛蛾幼虫。Calosoma sycophanta 比未感染的吉普赛蛾幼虫更喜欢受 Vairimorpha 感染的幼虫，并显着影响传播。5 当 C. sycophanta 在潜伏期被感染和未感染的幼虫一起饲养在笼子盆栽橡树树苗上时，测试幼虫中的 V. disparis 感染百分比增加了 70% 以上。在这些实验中，N. lymantriae 的传播没有受到显着影响。6 甲虫在以受感染的猎物为食后从未感染任何一种微孢子虫。7 我们得出结论，N. lymantriae 的传播不受影响。因为没有 V. disparis 孢子从活的幼虫中释放出来，